Annunciator ,Alarm,Nap-Zapper Place of Origin:China Zhejiang Brand ... patent product, electronic balanced anti-drowsy alarm, which is popularly callednap-zapper, is a high-tech product ... and his head nods forward, the alarm willbeep to arouse the alert of the driver and the passengers ... ) and comfortable enough even with glasses.Technical index:1) Alarm sensibility: alarming angle is: 15 - 20° (adjustable ...